Universal fixing bracket for photovoltaic panels

ABSTRACT

The present invention relates to a bracket used to fix photovoltaic panels in horizontal position on the roof, characterised in that it can be universally used on roofs made with flat surface and roofs made with notched panels provided with trapezoidal ribs, including with different cross-section.

The present patent application relates to a universal bracket used to fix photovoltaic panels in horizontal position on the roof.

As it is known, the use of photovoltaic panels for energy saving purposes has considerably increased, with special reference to warehouses for industrial or handicraft activities.

In fact, in this type of buildings, roofs are made with notched panels having a sandwich-like structure, being composed of a thick supporting layer of polyurethane foam and an upper sheet metal covering.

The market currently offers alternative versions of notched panels that differ in terms of the section used in the metal covering surface.

While all notched panels are characterised by the presence of a plurality of visible raised ribs, which are normally provided with trapezoidal cross-section, it is also known that said panels are not manufactured in a “harmonised” version, but in alternative versions that differ in the section used in the raised ribs.

It being understood that the ribs provided in the current models of notched panels basically have the same height, it must be noted that they differ in the width and inclination of the lateral sides.

Moreover, in other cases roofs are still made with traditional flat surfaces that are not provided with raised ribs.

In spite of the specific type of roofing used from time to time, the installation of photovoltaic panels on the roof can be carried out according to two alternative technologies.

According to a first technology, a grid of tubular bars is created on the roofing in order to support and fix the panels.

According to an alternative technology, a plurality of sturdy brackets is mounted on the roofing, from which threaded stems with vertical axis protrude in vertical direction.

Tubular bars are screwed on the threaded stems to support the photovoltaic panels.

According to the latter technology, the borders of two contiguous photovoltaic panels are arranged, on opposite sides, at the two sides of each fixing plate, in such a way that the threaded stem of the latter protrudes in vertical direction in intermediate position.

Then, a small plate suitably provided with a through hole is inserted on the stem, being adapted to be engaged from up down against the upper surface of the two contiguous photovoltaic panels, in such a way to prevent their accidental raising.

The brackets that are currently mounted on perfectly flat roofs consist in simple plates, preferably provided with a central deep-drawn section that protrudes in vertical direction, with a hole in which the threaded stem is inserted from down up.

In case of roofing made with notched panels, brackets are mounted “astride” each rib of the panels, in the points of the panels with maximum thickness and consequently maximum resistance.

For this reason the brackets adapted to cooperate with notched panels are provided with a basically overturned U-shaped section that allows them to be exactly overlapped on the ribs of the panel.

In order to achieve such a condition, the section of each bracket must perfectly match the section of the corresponding rib.

Considering that the market offers at least two versions of notched panels, one with ribs with higher width and one with ribs with lower width, it is evident that the brackets must be made in two different versions, each of them being adapted to adjust to only one of said types of ribs.

In view of these premises it appears evident that the installer of photovoltaic panels must be always provided with three types of supporting plates, since he may be asked to work indifferently on roofing with flat surface or notched panels with very wide ribs or notched panels with not very wide ribs.

The specific purpose of the present invention is to devise, for the first time, a universal bracket that is capable of being conveniently and indifferently fixed on roofs of the three types.

It must be said that the bracket of the invention, which is provided with a basically square shape, has a special concave cross-shaped structure in which the two arms of the cross consist of two rectilinear concave sections, with basically trapezoidal cross-section, provided with different inclination in the lateral sides and consequently with different width of the internal cavity.

In particular, one of these rectilinear concave sections is provided with a trapezoidal cross-section that allows it to be perfectly situated “astride” the ribs of the first type of notched panels used in roofs.

Likewise, the second of the rectilinear concave sections is provided with a trapezoidal cross-section that allows it to be perfectly situated “astride” the ribs of a second type of notched panels.

Four plates with central hole are provided at the base of a similar cross-shaped structure in intermediate position between the four arms of the cross.

Moreover, the four “angular” plates, as well as the upper wall of the two perpendicular arms of the cross-shaped concave structure, are provided with through holes to allow for the insertion, from up down, of fixing screws against the corresponding panels of the roofing.

In view of the above general description of the invention, it appears evident that the bracket of the invention can be correctly fixed on each one of the three types of panels for roofing.

In case of perfectly flat roofing, the installation of the bracket of the invention provides for engaging the bracket on the roofing in the four angular plates and fixing it with screws inserted from up down through the holes provided on the plates.

The coupling of the plates with the ribs of the notched panels is favoured by the presence of the concave trapezoidal sections, after selecting, from time to time, the section that complies with the specific section of the fixing rib.

It can be otherwise said that the operator provided with a bracket of the invention will be able to select the concave trapezoidal section that adjusts perfectly to the specific section of the ribs from time to time, by simply rotating the entire bracket by 90°.

Once a similar “male-female” coupling has been obtained between the bracket and the rib of the notched panel, they will be mutually and finally fixed by means of screws with vertical axis inserted from up down in the through holes provided on the upper horizontal wall of both trapezoidal sections.

In order to guarantee the higher fixing stability of the bracket of the invention, the same bracket can be provided with additional through holes (always adapted to receive corresponding screws) also in the lateral inclined sides of the two trapezoidal sections.

Of course, the bracket is provided in the centre of the concave cross-shaped structure with a large through hole from which the threaded stem of a bolt completely inserted inside it, from down up, can protrude in vertical direction.

For purposes of clarity, the description of the invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, wherein:

FIG. 1 is an axonometric view of the installation modes of the bracket of the invention on a roofing with flat surface;

FIGS. 2 and 3 are axonometric views of the installation modes of the bracket of the invention on two alternative types of notched panels, which only differ in the configuration of the trapezoidal ribs;

FIG. 4 is the same as the above figures, except for it refers to an alternative embodiment of the bracket of the invention;

FIG. 5 is an axonometric view that shows the bracket of FIG. 4.

Referring to FIGS. 1, 2 and 3, the bracket of the invention (1), which is provided with a basically square shape, has a cross-shaped box-like body, formed from the intersection of two rectilinear concave sections (2, 3) provided with a basically trapezoidal cross-section.

In actual fact, the first section (2) is provided with lateral sides (2 a) that are stretched more than the lateral sides (3 a) of the second section (3).

The upper horizontal wall of both sections (2, 3) is provided with circular through holes (2 b, 3 b), whereas an additional circular through hole (4) with larger cross-section is provided in the intersection point of the sections (2, 3).

The latter hole is crossed from down up by a corresponding threaded stem (10) with basically vertical axis, which is actually adapted to be used to fix the supporting structure of the photovoltaic panels.

Four basically square “angular” plates (5) are provided at the base of the cross-shaped box-like body, in intermediate position at the four arms of the body, each of them being provided with a central through hole (5 a).

In particular, FIG. 1 shows the fixing modes of the bracket of the invention (1) on a roof (S) with perfectly flat surface.

As mentioned earlier, in such a case, the bracket (1) is laid on the roof (S) on the angular plates (5)—that act as supporting feet—before being firmly fixed by means of screws inserted from up down in the through holes (5 a) of the plates (5) in such a way to be engaged with the roof (S).

FIGS. 2 and 3 show the bracket of the invention (1) in combination with two notched panels (P1, P2) that differ in the cross-section of the ribs (C1, C2).

The same specimen of bracket of the invention (1) can be exactly mounted astride either one of the ribs (C1, C2)—with the necessary interposition of a polyethylene gasket (6)—selecting the corresponding rectilinear section (2, 3) from time to time.

Once installation has been carried out as illustrated above, the coupling is stabilised using screws with vertical axis inserted from up down in the through holes (2 b, 3 b) of the sections (2, 3), in such a way to penetrate inside the polyurethane structure of the ribs (C1, C2) of the panel (P1, P2).

Attention is drawn on the fact that the gasket (6) used in case of notched panels is advantageously provided with double function.

On one hand, it prevents water infiltration towards the polyurethane internal structure of a panel (P1, P2) through the holes made on the ribs (C1, C2) during the installation of the fixing screws of the bracket (1).

On the other hand, because of the intrinsic elasticity of the polyethylene structure, the gasket (6) favours the ideal coupling of the two trapezoidal sections (2, 3) of the bracket (1) also on ribs of notched panels with not perfectly compatible cross-section.

It is certainly true that the specific shape given to the trapezoidal sections (2, 3) has been provided according to the two most popular types of notched panels for roofing.

Nevertheless, the market offers other versions of notched panels, which differ in the specific configuration of the trapezoidal cross-section of the ribs.

In these cases, the shape of the ribs would not be perfectly compatible with the shape of the trapezoidal sections (2, 3) of the bracket of the invention (1).

In such a case, the interposition of the gasket (6) is especially useful to offset the morphological differences between the cross-section of a rib of a notched panel and the section of one of the trapezoidal sections (2, 3) of the bracket (1) and consequently eliminate any possible “clearance” between them.

Upon the installation of the fixing screws, the gasket (6) is compressed tightly between the rib (C1, C2) of the notched panel and the trapezoidal section (2, 3) of the bracket (1), it being evident that such a compression will have higher or lower values according to the specific morphological difference between the cross-section of the rib and the cross-section of the trapezoidal section.

FIGS. 4 and 5 show an alternative version of the bracket of the invention (11) which is preferably made of moulded plastic materials.

The first peculiarity consists in the fact that the upper walls of the trapezoidal sections (2, 3) are bordered by raised edges (2 c, 3 c) on both sides.

Another peculiarity of this embodiment of the bracket of the invention (11) consists in the fact that it is provided with through holes (2 d, 3 d) for the insertion of fixing screws also on the inclined lateral sides (2 a, 3 a) of the two trapezoidal sections (2, 3).

Additionally, a concave appendix protruding in vertical direction is provided in the intersection point of the two trapezoidal sections (2, 3), which comprises a lower section (7) shaped as the polygonal head of a bolt and a basically cylindrical upper section (8), both being crossed by a hole with vertical axis (9).

The hole (9) is crossed from down up by the threaded stem (10) of a bolt, the head of which is exactly engaged—without possibility of rotating freely—into the polygonal lower section (7) of the appendix.

In this way, the head of the bolt creates no impediment on the lower side of the bracket (11), whereas the threaded stem (10) protrudes in vertical direction and is advantageously used to fix two contiguous photovoltaic panels (F).

Reference is made to FIG. 4, in which the threaded stem (10) is positioned between the borders of two contiguous photovoltaic panels (F) laid on opposite sides on the same specimen of bracket of the invention (11) exactly on the raised edges (2 c, 3 c).

In such a case a moulded plate (12) is inserted along the stem (10) from up down, which is positioned on the borders of the two contiguous photovoltaic panels (F) and firmly fixed in such a position by means of a fixing nut (13).

It must be said that the latter version of the bracket of the invention (11) is preferably made of moulded plastic materials, just like the plate (12) used to fix the photovoltaic panels (F) with metal structure.

When the latter panels (F) are laid on the raised edges (2 c, 3 c) of the bracket of the invention (11), they are prevented from getting in direct contact against the metal head of the fixing screws inserted from up down in the holes (2 b, 3 b) provided on the trapezoidal sections (2, 3).

This is to say that the presence of the raised edges (2 c, 3 c) allows for obtaining electrical insulation between the photovoltaic panels (F) and the fixing screws, which is useful to prevent the occurrence of stray currents, when the bracket (11) is moulded from non-conductive material, such as plastics. 

1. Universal fixing bracket for photovoltaic panels, characterised in that it is provided with a basically cross-shaped box-like body, formed from the intersection of two rectilinear concave sections (2, 3), both being provided with trapezoidal cross-section, but with lateral sides (2 a, 3 a) with different inclination.
 2. Universal bracket as claimed in claim 1, wherein the base is provided with four plates (5) in intermediate position between the four arms of the cross-shaped box-like body.
 3. Universal bracket as claimed in claim 1, wherein the upper horizontal wall of each trapezoidal section (2, 3) is provided with one or more circular through holes (2 b, 3 b) to receive fixing screws.
 4. Universal bracket as claimed in claim 1, wherein the inclined lateral sides (2 a, 3 a) of each trapezoidal section (2, 3) is provided with one or more circular through holes (2 d, 3 d) to receive fixing screws.
 5. Universal bracket as claimed in claim 1, wherein it is provided with pairs of raised edges (2 c, 3 c) in lateral position on the upper sides of the trapezoidal sections (2, 3).
 6. Universal bracket as claimed in claim 1, wherein it is provided with a circular through hole (4) in the intersection point of the trapezoidal sections (2, 3), which is exactly crossed by the threaded stem (10) of a bolt inserted in the hole (4) from down up.
 7. Universal bracket as claimed in claim 1, wherein it is provided with a concave appendix that protrudes in vertical direction in the intersection point of the trapezoidal sections (2, 3), which is composed of a lower section (7) shaped as the polygonal head of a bolt and a basically cylindrical upper section (8), both being crossed by an axial hole (9) adapted to be penetrated by the threaded stem of a bolt that is inserted in the appendix from down up, in such a way that the polygonal head is exactly engaged in the lower section (7).
 8. Universal bracket as claimed in claim 1, wherein it is provided with a gasket (6) made of polyethylene or other intrinsically elastic materials, which are capable of perfectly adhering to the internal walls of one of the trapezoidal sections (2, 3).
 9. Universal bracket as claimed in claim 1, wherein it is made of moulded plastic materials. 